Shoe moulds

ABSTRACT

There are disclosed in the present application moulds for producing shoes having soles moulded directly to the upper or separately moulded soles in which there is included means for positioning component shoe bottom parts in the mould preparatory to moulding. The component parts which include decorative edges or foxing and tread inserts for soles are retained by vacuum in the mould. When the sole is being moulded directly to the lasted upper, an insole is positioned and retained in place by vacuum acting through openings in the bottom of the last.

United States Patent 1191 1111 3,855,657 Mazzotta Dec. 24, 1974 [54] SHOE MOULDS 3,477,096 11/1969 Bowles et al 425 405 [76] Inventor: G. James Mazzotta, 40 Waite St.

Extensicm Malden Mass. 02148 Primary ExammerPatr1ck D. l awson Attorney, Agent, or Firm-Maunce R. Bolteau [22] Filed: Nov. 12, 1973 [21] App]. No.: 414,728 ABSTRACT There are disclosed in the present application moulds [52] U S Cl l2/142 RS 425/405 for producing shoes having soles moulded directly to [51] 9/00 b 21/00 the upper or separately moulded soles in which there [58] Field 425/465 DIG is included means for positioning component shoe bot- RS 6 tom parts in the mould preparatory to moulding. The component parts which include decorative edges or foxing and tread inserts for soles are retained by vac- [56] References Cited uum 1n the mould. When the sole is belng moulded d1- UNITED STATES PATENTS rectly to the lasted upper, an insole is positioned and 3,109,701 11/1963 Jacquet 12/142 RS retained in place vacuum acting through Openings Rollman et al l2/l42 RS in the bottom of the last 3:466:684 9/1969 Rollman 12/142 RS 11 Claims, 7 Drawing Figures SHOE MOULDS The present invention relates generally to improvements in moulds employed in the manufacture of shoes and in methods of producing shoes and shoe parts. More particularly, the invention relates to moulds including means for positioning component parts preparatory to injection.

An economical method of producing a shoe consists of mounting the upper on a metal last and moulding an outsole in situ on the shoe bottom. Alternatively a separately moulded heel and sole combination commonly known as a unisole is premoulded and secured to the shoe bottom by means of an adhesive. A common material for moulding in situ and for pre-moulding unisoles is polyvinyl chloride or PVC. Also useful for moulded shoe bottoms are a wide variety of other plastic resins and natural and synthetic rubbers. In any event, both processes conventionally suffer from lack of styling flexibility and from the need to perform manually various auxiliary operations. As a result, it is difficult to obtain stylish shoes by this process and the manually performed operations add unduly to manufacturing costs.

It is accordingly an object of the present invention to improve the styling possibilities of shoes having moulded soles.

Another object is to reduce the cost of producing shoes having soles moulded in situ by combining operations which have heretofore been performed manually after the moulding operation.

Still another object is to improve the flexibility in both production and styling of shoes having moulded soles.

The foregoing objectsrare achieved according to the invention by a mould having a plurality of passages in one or more of its interior surfaces communicating through appropriate manifolds with a source of vacuum. For moulding in situ, there is conventionally employed moulding apparatus consisting of a bottom or sole mould, separable side moulds each carrying a welt plate and a metal last upon which the upper is mounted and lowered to-close the top of the mould by slightly indenting the upper against the welt plates while the side moulds are brought together or closed. In order to facilitate the application of a foxing or decorative edge to the sole during the moulding process, there are provided according to a feature of the invention passages in the side moulds communicating with a vacuum or suction source through manifolds formed in the bodies of the moulds. For retaining a tread insert such as a leather tap in the sole, the bottom or sole mould is formed with a manifold in communication with vacuum passages appropriately positioned to hold the tread insert. A vacuum arrangement including passages in communication with the last bottom is provided to retain an insole on the last preparatory to mounting of the upper so that the sole which is moulded directly on the shoe bottom adheres to the insole and there is consequently no need for a time consuming secondary operation after the sole has been moulded.

The foregoing objects and features together with numerous advantages of the present invention will be more fully understood from a detailed description of an illustrative embodiment taken in connection with the accompanying drawings in which:

FIG. 1 is a view in perspective of an apparatus for moulding a sole directly upon a shoe bottom including side moulds and, shown in separated relationship for clarity, a lasted shoe upper and a sole mould;

FIG. 2 is a plan view of the sole mould and the side moulds of FIG. 1, the side moulds being shown opened;

FIG. 3 is a view in perspective of one of the side moulds showing its interior moulding surfaces together with a nest in which a foxing is held by suction;

FIG. is a view in cross-section showing a lasted shoe upper, a sole mould and an alternate form of side moulds;

FIG. 5 is a view in perspective and partly in section showing the interior construction of a unisole mould including a vacuum retainer for foxing;

FIG. 6 is a view in cross-section of a last forming a part of a mould for producing an outsole directly upon a shoe bottom, including a vacuum arrangement for holding an insole on the last bottom; and

FIG. 7 is a view in perspective and partly sectioned of a canvas shoe or sneaker produced by apparatus according to the invention.

Turning now to the drawings, particularly FIGS. 1 to 3 inclusive, there is shown a mould assembly for producing a sole directly on the bottom of a shoe. The assembly comprises left and right side mould members indicated respectively at 10 and 12, a sole mould member indicated generally at 14 and a foot form or last indicated generally at 16. The side mould members 10 and 12 together with the sole mould 14 when the side mould members are closed as shown in FIG. 1 define a cavity whichis closed by the last 16 upon which an upper 18 is mounted to produce a sole directly on the bottom of the shoe in the usual manner. The upper 18 is that of a sneaker as also shown in FIG. 7 but it will be appreciated that the direct moulding of shoe soles to uppers may be accomplished with leather uppers in a comparable generally conventional manner. As will be seen, however, features'of the invention relate to the production of a shoe including one or more of the following: a foxing 20, a tap insert 22, and an insole 24. All of these components are currently being included in shoes having moulded soles but their inclusion requires either added operations or results in greatly reduced productivity in the sole moulding operation.

The side mould members 10 and 12 together with the sole mould 14 combine to produce an open-topped sole moulding cavity which is closed by the last mounted upper 18. Each mould member includes vacuum perforations for retaining a component part within the moulding cavity to be bonded to the shoe bottom by the injected plastic. Thus, each of the side mould memhers is formed in its moulding surface with a channel or nest 26 of appropriate width and depth to receive the intended foxing as best seen in FIG. 3. Cut into the body of the mould members 10 and 12 are manifolds 28 which communicate with the nest 26 through a plurality of perforations 30, whose number and size depend upon the characteristics of the foxing being used. Thus the foxing 28 shown particularly in FIGS. 3 and 7 is of braided rope'to simulate a rope sole. Such foxing which is very porous requires a relatively greater number of perforations 30 of a smaller diameter than would be employedif the foxing were a non-porous printed tape, for example. The manifolds 28 are closed by a dam 32 at each end and their upper surface is covered by a welt plate 34. Each of the manifolds is placed in communication with a source of vacuum through a flexible hose 36 connected to the manifold through the welt plate 34. Injection of molten plastic takes place through a conduit 38 communicating with the interior of a mould at a point on the parting line of the side moulds above the sole mould member 14 in the heel region of the shoe bottom.

The sole mould member 14 is formed with an upper moulding surface adapted'to produce the tread surface of a combination sole and heel directly on the shoe bottom. In the sole portion of the moulding surface, the mould member 14 is formed with a plurality of perforations 44 in a top plate 45, which communicate with a manifold comprising a longitudinally drilled hole 46 plugged at its outer end and connected to a chamber 47. The manifold is connected to a vacuum conduit 48 through a vertical passage 50. A source of air under pressure is also connected to the manifold through a second conduit 52 and a vertical passage 54 intersecting the hole 46. Appropriate external valving is provided to shift from vacuum for holding the tap insert preparatory to moulding, to compressed air for assisting in the release of the shoe from the mould.

The last 16 is similarly provided with vacuum means for holding an insole on its bottom when the upper, as is commonly the case in the manufacture of sneakers, is string lasted or stretched over the last by means of a drawstring sewn to its bottom edge. Conventional practice is to mould the sole onto the upper and thereafter to secure the insole by adhesive to the inside of the shoe. This method while requiring an additional operation after sole moulding is frequently not entirely satisfactory because of the failure of the adhesive. For vacuum holding, the last 16 as shown in FIGS. 1 and 6 is formed with a manifold chamber 58 covered by a perforated plate 60. As in the case of the sole mould 14, the chamber 58 is also connected to sources of vacuum and of compressed air through hoses 62 and 64 respectively communicating with the chamber through obliquely drilled passages 66 and 68. As in the case of the vacuum and compressed air sources associated with the sole mould member 14, an external valving arrangement is employed to connect either a source of vacuum to the hose 62 for holding an insole on the bottom of the last 16 or a source of air under pressure to the hose 64 to assist in removing the shoe from the last after the sole has been moulded.

There is shown in FIG. 4 an alternative construction in which side mould members 72 and 74 are mounted in mould carriers 76 and 78 respectively, being retained in the carriers by a plurality of screws 80. Each insert 72 and 74 is located in its appropriate carrier I against a shallow abutment 82 and the carriers are FIGS. 1 to 3 inclusive. However, a basic advantage of the mould assembly shown in FIG. 4 is that changes may be made in the moulds at a considerable saving in cost and effort to accommodate a variety of sizes and styles merely by replacing a thin inner shell consisting of the inserts 72 and 74.

In FIG. 5, there is shown a mould assembly for producing unisoles to be adhesively secured to the bottom of shoes. The mould assembly comprises bottom and top mould members 92 and 94 respectively. In the bottom mould 92, there is formed a cavity for moulding essentially all the surfaces of the combination sole and heel which will be visible when the unisole is secured to the bottom of the shoe. Included in the bottom mould member 92 isa foxing locating channel 96 in communication through a plurality of passages 98 with a manifold 100 which is in turn connected through a tube 102 to a source of vacuum. The top surface of the mould member 92 is closed by a plate 104. Molten plastic is injected into the cavity through a conduit 106 and the cavity is formed with sufficient draft that the moulded sole may be lifted out of the cavity in the bottom mould member 92 after the upper member 94 has been raised. The upper mould member 94 includes surfaces for moulding the entire surface of the sole and heel combination to be cemented to the bottom of the shoe. In addition, there is included as an integral part of the upper mould member 92 a depending lip 108 which forms the upper edge of the channel 96, thereby facilitating removal of the sole by eliminating undercuts in the mould.

In using the mould assembly according to the invention, one or more of the vacuum holding features may be employed. If all of the features are employed, the insole 24 is first mounted. on the bottom of a last 16 before the upper 18 is string-lasted with its margin surrounding the insole. Then, the side mould members 10 and 12 being closed, the required length of foxing 20 generally completely surrounding the sole is inserted into the channel 26 and the tap 22 is laid on the sole mould 14, all the component parts being retained by vacuum preparatory to the injection of plastic into the mould. The lasted upper 18 is then lowered into engagement with the welt plates 26 before injection. After the moulding has occurred, the side mould members 10 and 12 are opened, compressed air is directed through the manifolds 46 releasing the shoe from the sole mould and finally to the manifold 58 to assist in removing the completed shoe from the last 16.

Throughout this specification, moulding has been referred to as an injection of moulten plastic into a mould cavity. It will be appreciated, however, that with slight modification, if any, the mould features of the present application are equally applicable to the manufacture of shoes having bottoms moulded of natural and synthetic rubbers and other materials which may not be considered as plastic.

Having thus disclosed my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A shoe sole moulding assembly comprising a mould body having interior side and bottom walls defining at least a portion of a cavity for forming the edge and tread of a sole respectively, a channel formed in the side wall adapted to locate a foxing and-vacuum means connected to the channel for retaining the foxing until after sole material has been injected into the cavity.

2. A moulding assembly according to claim 1 further characterized in that the vacuum means comprises a manifold formed in the mould body and connected to a source of vacuum. I

comprising a sole mould member in which the bottom wall of the cavity is formed and vacuum means including a manifold chamber for retaining a tread insert on the sole mould member.

7. A moulding assembly according to claim 6 further comprising means for connecting a source of compressed air to the chamber.

8. A method of producing a shoe comprising the I steps of mounting an upper on a last, providing a sole mould assembly having a locating channel in its sole edge moulding surface, connecting the channel to a source of vacuum, inserting a decorative foxing in the channel to be retained by the vacuum and injecting molten sole material intothe mould to produce a sole bonded directly to the shoe upper and having a foxing covered edge.

9. A method according to claim 8 further comprising the step of retaining an insole by vacuum on the bottom of the last preparatory to mounting the upper.

10. A method according to claim 8 further comprising the step of retaining a tread insert in the sole mould.

11. A method according to claim 9 further comprising the step of retaining a tread insert in the sole mould. 

1. A shoe sole moulding assembly comprising a mould body having interior side and bottom walls defining at least a portion of a cavity for forming the edge and tread of a sole respectively, a channel formed in the side wall adapted to locate a foxing and vacuum means connected to the channel for retaining the foxing until after sole material has been injected into the cavity.
 2. A moulding assembly according to claim 1 further characterized in that the vacuum means comprises a manifold formed in the mould body and connected to a source of vacuum.
 3. A moulding assembly according to claim 1 further comprising a last adapted to receive a shoe upper and to close the mould cavity.
 4. A moulding assembly according to claim 3 further comprising a plurality of passages on the bottom of the last connected to a vacuum source for retaining an insole to the last bottom.
 5. A moulding assembly according to claim 4 further comprising means for connecting a source of compressed air to the passages for assisting in removing a completed shoe from the last.
 6. A moulding assembly according to claim 1 further comprising a sole mould member in which the bottom wall of the cavity is formed and vacuum means including a manifold chamber for retaining a tread insert on the sole mould member.
 7. A moulding assembly according to claim 6 further comprising means for connecting a source of compressed air to the chamber.
 8. A method of producing a shoe comprising the steps of mounting an upper on a last, providing a sole mould assembly having a locating channel in its sole edge moulding surface, connecting the channel to a source of vacuum, inserting a decorative foxing in the channel to be retained by the vacuum and injecting molten sole material into the mould to produce a sole bonded directly to the shoe upper and having a foxing covered edge.
 9. A method according to claim 8 further comprising the step of retaining an insole by vacuum on the bottOm of the last preparatory to mounting the upper.
 10. A method according to claim 8 further comprising the step of retaining a tread insert in the sole mould.
 11. A method according to claim 9 further comprising the step of retaining a tread insert in the sole mould. 